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A. DROIT. APPARATUS FOR THE MANUFACTURE OF [SODA BY AMMONIA. No. 369,104. Patented'Aug. 30, 1887..

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" UNITED STATES PATENT OFFICE ALBERT DROIT, OF PARIs, FRANoE, AssIeNoR To THE sooIETE ANONYME POUR LETUDE ET LA. oREATIoN DE soUDIEREs.

APPARATUS FOR THE MANUFACTURE OF SODA BY AMMONIA.

. SPECIPICATION'forming part of Letters Patent No. 369,104, dated August 30, 1887.

Application filed August 31, 1886. Serial No. 212,289. (No model.)

To all whom it may concern:

Be it known that I, ALBERT DROIT, a citizen of the Republic of France, residing in Paris, in said Republic, have invented new and useful Improvements in Apparatus for the Manufacture of Soda by Ammonia, of which the following is a specification.

This invention consists in improvements in the carbonating apparatus and in the ammonia-regenerating apparatus which are employedin the manufacture of carbonate ofsoda by the ammonia process.

The invention is fully illustrated in the accompanying drawings, in which- Figure 1 represents a central vertical section of the carbonating apparatus. Fig. 1 represents a horizontal section of the same. Fig. 1" represents a transverse section of one of the annular plates of said apparatus and side views of the braces for supporting the same. Fig. 2 represents an elevation, partly sectional, of the ammoniaregenerating appa- Fig. 2 represents a vertical section of the upper distilling-column of said apparatus. Fig. 2 represents a horizontal section corresponding with Fig. 2. Fig. 2 represents a vertical section corresponding with Fig. 2. Figs. 2 and 2 represent horizontal sections corresponding with Fig. 2".

Similar letters of reference indicate corresponding parts in all the figures.

I will first describe the carbonating apparatus. As is well known, the first operation in the manufacture of soda has for its object the carbonating of an ammoniacal solution of chloride of sodium or brine, in order to produce the precipitate of bicarbonate of soda. As is also well known, it suffices for that purpose to bring carbonic-acid gas into intimate and diffused contact with the solution or brine; but this operation, very simple in theory, is difficult to realize in practice, and requires the employment of special apparatus. In fact, the carbonic gas employed is not pure. It has divers sources, and never contains more than thirty to forty per cent. of gas, (G0,) In order that it should react well upon the brine, and that it should be well utilized, it is necessary, first, that it should be infinitesimally divided and diffused among the brine under treatment, and that it should be retained therein as long a time as possible; second, that the precipitate formed should be maintained in suspension, to prevent the choking of the apparatus and produce bicarbonate sufficiently grained and crystallized; third, that the reaction should be made methodically-that is to say, that the gas rich in carbonic acid should be brought in contact with the partly-spent liquids, and that the gas which is about to leave the apparatus should come in contact with liquids rich in ammonia; fourth, that the heating of the apparatus, due to the reactions which take place, should be easily counteracted or prevented; fifth, finally, that the exhaustion of the ammonia produced by the passage of the gases should be as feeble as possible.

The object of my invention, so far as it relates to the carbonating apparatus, is to provide an apparatus which fulfills all the above conditions more perfectly.

My improved apparatus differs from carbonating apparatus previously employed chiefly in that it is composed of a cylindrical annular vessel, V, Figs. 1 and 1, containing numerous annular baffle-plates, p, slightly convex and toothed on the edges. These plates are supported on flanges provided in the casting of the walls of the vessel and on the transverse braces T thereof.

The apparatus being full of ammoniacal brine up to A, the brine arrives therein continually by the tube 13 and accumulates there The carbonic-acid gas, more or less pure, arrives by the tube 0. It is divided, first, by the toothed crown D. Then it is infinitesimally divided by the teeth of all the plates, which are interposed in such manner as to obstruct or retard the passage between them. The liq-- uid and its precipitate of bicarbonate of soda are extracted from time to time by the tube R, furnished with a cook? The gas is then obliged to be often divided in a feeble vertical current, and it is thus retained as long a time as possible in the liquid, which realizes the first conditions of which Ihave above spoken.

It is manifest that the annular arrangement, while giving a sufficient volume to the apparatus,permits the reduction'of the distance of the walls of the vessel in such mannerthat the agitation of the liquid is made in all parts and.

that-the precipitate is maintained well in suspension, as is desirable.

An important advantage of the annular arrangement of the plates is to permit an energetic refrigeration by causing the flow of water upon the exterior surfaces of the apparatus, while these surfaces are greater for the same volume of liquid under treatment than in ordinary apparatus of simple cylindric form heretofore employed.

Another advantage results from the division of the gas by the teeth on the plates pviz., that the ammonia passes through theliquid slowly enough for the reaction to be offected, and that very little ammonia passes off. Vhat ammonia does pass off is afterward recovered by the washing of the gas in the washers, which it is unnecessary here to describe. The division of the gas being very great and often repeated, the reaction between the ammoniacal liquid and the carbonic gas is very energetic, and the apparatus does not require to have a'great height.

The liquid drawn off from the carbonating apparatus is conducted to special filters,where the precipitate of bicarbonate of soda from the mother waters is effected. These mother waters contain ammonia in different conditions. It is necessary to regenerate this gas to use it for new ammoniacal brines.

It is well known that by bringing the liquid to a state of ebullition the ammonia freed or combined with the acid 00, is disengaged. At the same time the bicarbonate of soda in solution decomposes a part of the chloride of ammonia. The liquid then contains no more chloride of ammonia than can be decomposed by the lime and driven off as AZH, by heat. These operations present certain practical difficulties: first, there are great quantities of liquid to be treated; second, the treatment should be continued without the apparatus choking by excess of lime; third, the two principal operations of which I have spoken should be made successively and completely; fourth, the residuary liquids to be expelled should not contain any ammonia.

The object of my invention, so far as it relates to the regeneration of the ammonia, is to overcome the practical difficnlties hereinabove mentioned.

My improved regenerating apparatus is composed of two distilling-columns, as follows: The upper column, A, is formed of several plates, upon which are arranged several bells toothed at their edges. These plates are all covered with a certain quantity of liquid to be distilled, of which the level is regulated by the arrangement of the overflows t, placed external and on the same side of the column. Each plate is divided on aportion of its length by a partition, 0, which compels the liquid which arrives On the plate by one overflow, i, to flow all around the plate to reach the next overflow. The liquid to be distilled arrives constantly by a siphon-tube, D, upon the upper plate, and flows thence over all the plates of the column. The gas and vapor which pass through the column from bottom to top arrive under the bells by the tubes 2), and, falling through the liquids, produce, by all the teeth on the edges of the bells, an energetic agitation, which facilitates the passing off of the ammonia and of the carbonic acid. The temperature, which is moderate in the upper part of the column, is more considerable in the lower part, and is intended to produce an ebullition of the liquid in such manner that there remains in it neither carbonic acid nor free ammonia. In each plate there is a hole fitted with a plug, F, which may be raised through an opening in the side wall to permit the emptying of all the plates when it is desired to disconnect the overflows or open the large man-holes G. The gases disengaged escape by the upper tube, H, and, passing through a refrigerator which it is not thought necessary to show--then go to be condensed in the brine. The lower column, B, wherein is performed the treatment by lime, contains several toothed plates, in which are openings covered by bells K K, toothed on one side and placed opposite each other. Overflows T are arranged on the man-hole plates and serve for the circulation of the liquids; and as these overflows are arranged on opposite sides of the plates the liquid which circulates travels between the bells K and is agitated in all parts. Milk of lime arrives constant-1y by the tube M upon the upper plate, and the liquid coming from the upper distilling-column arrives at the same time by the communicating tube N. It is then upon this plate that there is produced the reaction of the lime upon the chlorhydrate of ammonia, and the passing off of the ammonia takes place successively over the other plates.

The heating of the apparatus is done by means of a tubular heater, S, heated by steam under pressure, while the liquid charged with lime, which accumulates at the lower part of the column, circulates in the tubes of the heater. The heating has the advantage of not diluting the liquids under treatment, as takes place when heating is effected by steam passing through the liquid. From time to time a part of the residuary liquids are evacuated by the cock U, Fig. 2. A steam-pipe, X, Fig. 2, permits the heating also by direct steam in case of necessity.

\Vhat I claim as my invention, and desire to secure by Letters Patent, is-

1. The combination of the annular cylindrical vessel V and its contained'interposed annular toothed plates, substantially as herein described, constituting the carbonating apparatus.

2. The combination of the upper and lower columns, A and 1B, the upper one, A, being divided by scparating-plates into superposed compartments, which communicate by ovcrflow-passages 1.,all on one side,and by means of orifices E in the said plates and toothed bells covering the said orifices, and which are themselves divided by partitions'O between the Intestimonywhereoflhavesigned thisspecisaid orifices E, and the lower one, B, which fication in the presence of two subscribing witis heated by steam, being divided by separatnesses. ing plates into superposed compartments,

5 which communicate by overflow-pipes T on ALBERT DROIT.

opposite sides, and by orifices in said plates and toothed bells covering said orifices, the Witnesses: whole constituting'a regenerating apparatus OH. CREMERS, for the ammonia, substantially as herein de- EDWARD P. MACLEAN.

1o scribed. 

